PoE module problem 3560

We are experiencing two of our layer 3 switches (3560 PoE and 3750 PoE) switches giving us problems with giving power to IP phones. These switches have an embedded PoE module and would previously give power to all IP phones on all its ports. Now all of a sudden over the past few months 6 of these ports have stopped powering phones. The phones are the same ie. 7911 and they take less than 15.4 W. We believe that the PoE module has started malfunctioning and has stopped giving power to all the ports. The port 'grants' power and then removes it. Below is a link showing all the messaged we receive on the terminal session. Please suggest what may be the problem and whether it is or is NOT a hardware fault with the PoE: